Technical Field
The present disclosure generally relates to audio output devices coupleable to an audio source via a wireless communication protocol such as Bluetooth. More particularly, but not exclusively, the present disclosure relates to a mechanism to mute and unmute the audio output device.
Description of the Related Art
Wireless protocols have been developed to convey information between devices in close proximity to each other. In many cases, the devices are within 10 feet of each other; however, the protocols often permit communication between devices that are up to 30 feet apart or even 300 feet apart. One such protocol conforms to a standardized specification managed by the Bluetooth Special Interest Group (SIG).
Several thousand companies participate in the BLUETOOTH SIG as members. The SIG administers and maintains the standardized Bluetooth protocol specification and also provides qualification testing of devices that wish to bear one or more of the Bluetooth trademarks. Funding for the Bluetooth SIG is provided by patent and trademark license fees paid by companies whose devices comply with the protocol. Bluetooth-compliant devices manufactured by one company are capable of communicating with Bluetooth-compliant devices manufactured by another company.
Fundamentally, the Bluetooth protocol is a low-power, high-speed wireless link technology used to pass data between audio devices (e.g., speakers, headphones), mobile devices (e.g., smartphones, laptops, and other portable equipment), entertainment devices (e.g., stereos, set top boxes, and the like), and other devices with little or no configuration or set up by a user. Bluetooth does not require devices to be positioned within line-of-sight of each other. The Bluetooth protocol uses small, inexpensive variations of existing wireless local area network (LAN) schemes. Often, a single integrated circuit chip is used to implement most or all of the low power logic of a Bluetooth-compliant device.
In some cases, Bluetooth capability is included within equipment, and in other cases, Bluetooth devices are provided as optional extras to add functionality to other devices.
When one Bluetooth-compliant device comes within range of another (e.g., between 10 cm and 100 m) the devices automatically exchange address and capability details. They can then establish a communicative link that transfers data at a specified rate such as 1 megabit per second (Mbps), 2 Mbps, or some other rate. The devices also negotiate or confirm other aspects of the communicative link such as what security (e.g., encryption, verification) and error correction methodologies will be used.
At the circuit level, each Bluetooth-compliant device includes a short-range transceiver. Communication through the transceiver is conducted over at least one data channel and/or up to three voice channels. Each Bluetooth-compliant device has a unique 48-bit address, and the addresses are embedded in packets of data so that data can be efficiently filtered and passed or ignored at the hardware-level. Connections between Bluetooth-compliant devices can be point-to-point or multipoint. A frequency-hopping scheme shared by linked devices provides security as well as protection from radio interference.
Bluetooth-compliant devices are often battery powered. Accordingly, power efficiency may be an important characteristic. The Bluetooth specification addresses power consumption with a “hold” mode, and often, a Bluetooth-compliant device will automatically shift to a low-power mode when traffic volume lessens or stops.
When two or more Bluetooth-compliant devices come into proximity with each other, a network may be instantly formed. The network may be considered a “piconet.” A piconet is a plurality of Bluetooth-compliant devices communicatively coupled in an ad hoc fashion. A piconet can be formed between two devices or with more than two devices.
A Bluetooth-compliant device joined in one piconet can also be a member of another network (e.g., another piconet) by means of time multiplexing. In such a scheme, the Bluetooth-compliant device joins multiple networks by suitably sharing time.
A Bluetooth system supports point-to-point and point-to-multi-point connections. When one Bluetooth-compliant device is connected to another such device, the connection is considered to be a point-to-point connection. Alternatively, when a Bluetooth-compliant device is connected to more than one Bluetooth-compliant device (e.g., up to 7 devices), it is a point-to-multipoint connection.
In a network configuration, one Bluetooth-compliant device may act as a master; one or more other Bluetooth-compliant devices may act as slaves. The clock and hopping sequence of the master unit are used to synchronize the other devices (i.e., the slave devices). In addition, in some cases, a 3-bit media access control (MAC) address is used to distinguish between each Bluetooth-compliant device that participates in a communicatively linked relationship.